Sullair SD-220 - Page 19

INSTALLATION, START-UP & MAINTENANCE MANUAL
MODEL NO.: SD-220 TO SD-600- DDS OPTION
REV 0 – May 24,,.2001
19
SECTION 3
3.3.2 DDS Controls – Start up and operation (Continued)
The POWER ON position will allow the hygrometer to be energized yet force the
dryer to operate on a FIXED CYCLE mode. The dryer SHOULD BE OPERATED IN
THIS POSITION AT TIME OF INITIAL STARTUP AND AT ALL TIMES WHEN THE
HYGROMETER OR HUMIDITY PROBE ARE REMOVED FOR SERVICE OR
CALIBRATION.
The DDS ON position will control the dryer regeneration steps when the dewpoint
of the dryer is better than the factory adjusted setpoint programmed into the digital
hygrometer.
The startup procedure for the DDS system will be as follows. Refer to the assembly
drawing in the following section.
1. Verify that the sample line (1/8 Teflon tube) is connected from the dryer outlet (see flow
schematic enclosed) to the inlet valve on the humidity probe sample cell. The humidity
probe comes in a transport container found inside the control panel. Remove probe from
container, and install in sample humidity cell. Close the container and keep inside the
control panel for future maintenance.
2. Connect the coaxial cable to the humidity probe
3. Fully open the inlet valve to the sample cell
4. Partially open the discharge valve of the sample cell to bleed off a small amount of
sample air. Do not fully open discharge valve
5. Perform a soap test to verify for leaks on all parts of the sample line connections and the
humidity sample cell.
6. The digital display will now read the dewpoint of the dryer system. It will take a short
period of time for a humidity probe to be purged of humidity.
Humidity cell assembly